Cooling plate and shelf structure



1965 R. EICHHORN ETAL 3,232,063

COOLING PLATE AND SHELF STRUCTURE 5 Sheets-Sheet 1 Filed June 26, 1964 fnveni'o'vw JZOberZLE' Gerhard C. 523%, "Duane CJYL C/L 1966 R. L. EICHHORN ETAL 3,232,063

COOLING PLATE AND SHELF STRUCTURE 5 Sheets-Sheet 2 I I }1 l Filed June 26, 1964 Feb. 1, 1966 R. L. EICHHORN ETAL COOLING PLATE AND SHELF STRUCTURE 5 Sheets-Sheet 5 Filed June 26, 1964 United States Patent 3,232,063 CGOLING PLATE AND SHELF STRUCTURE Robert L. Eichhorn and Gerhard C. Stoli, Benton Harbor, and Duane C. Nichols, St. Joseph, Mich, assignors to Whirlpool Corporation, a corporation of Delaware Filed June 26, 1964, Ser. No. 378,157 11 Claims. (Cl. 62-3) This invention relates to heat transfer apparatus, and in particular to apparatus for selectively refrigerating or heating a chamber and objects disposed within in the chamber.

A principal feature of the present invention is the provision of a new and improved heat transfer apparatus arranged for improved selective refrigeration or heating of a chamber and objects disposed therein.

Another feature of the invention is the provision of such an apparatus including means defining a chamber, means defining a heat transfer body having first and second portions in heat transfer association with each other and with the chamber, means for causing a first temperature difference between the first portion of the body and the chamber to cause a heat transfer therebetween, and means for causing a second temperature difference, greater than the first temperature difference, between the secend portion of the body and the chamber to cause a heat transfer therebetween.

A further feature of invention is the provision of such an apparatus wherein the heat transfer body comprises a monolithic structure defining a wall panel for heat transfer with the chamber and a shelf for supporting objects to be refrigerated or heated.

Still another feature of the invention is the provision of such an apparatus wherein the wall panel is selectively refrigerated or heated by thermoelectric means arranged in single stage configuration, and the shelf is concurrently refrigerated or heated by thermoelectric means arranged in cascaded multistage configuration.

Still another feature of the invention is the provision of such apparatus including means for selectively reversing the energization of the thermoelectric elements whereby the heat transfer means may be employed to heat the chamber and objects placed on the shelves, whereby the apparatus effectively comprises an oven.

Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings wherein:

FIGURE 1 is a horizontal section of a heat transfer apparatus embodying the invention, the front portion of the cabinet being shown in top plan view;

FIGURE 2 is a fragmentary vertical section taken substantially along the line 22 of FIGURE 1;

FIGURE 3 is a fragmentary vertical section taken substantially along the line 3-3 of FIGURE 1;

FIGURE 4 is a fragmentary vertical section taken substantially along the line 4-4 of FIGURE 1; and

FIGURE 5 is a schematic diagram illustrating the electrical circuitry of the apparatus.

In the illustrative embodiment of the invention as disclosed in the drawing, a heat transfer apparatus generally designated is shown to comprise an insulating cabinet 11 having side walls 12 and 13, rear wall 14, top wall 15, bottom wall 16, and a removable front closure 17 cooperatively defining an interior chamber 18. The present invention comprehends an improved apparatus generally designated 19 for effecting a heat exchange relative to the chamber 18. Thus, the apparatus 19 is selectively operable to heat the chamber 18 thereby causing the apparatus 10 to be an oven apparatus, or selectively refrigerate the chamber 18, thereby causing the apparatus 10 to be a refrigeration apparatus. In illustrat- 3,232,063 Patented Feb. 1, 1966 ing the invention, the apparatus 10 will be described in its operation as a refrigeration apparatus.

More specifically, apparatus 19 comprises a heat exchange panel 20 and a plurality of shelves 21 and 22 comprising a monolithic structure formed of a thermally conductive material such as aluminum. A plurality of bosses 23, 24, 25, 26, 27 and 28 project rearwardly from the panel 26 respectively into thermal contact with a plurality of thermoelectric devices 29, 30, 31, 32, 33 and 34. By suitably energizing the thermoelectric devices 29 through 34, the apparatus 19 causes the panel 20 and shelves 21 to serve selectively as a refrigerating panel and cold shelf structure, or a heating panel and heater structure. Thus, assuming that the thermoelectric elements are energized so as to absorb heat from the panel 20 and shelves 21 and 22, the apparatus 10 functions as a refrigerator wherein the chamber 18 is refrigerated to a preselected low temperature and the shelves 21 and 22 function as cold shelves for cooling or freezing objects placed thereon.

As best seen in FIGURES 1, 3 and 4, the panel 20 is provided with a plurality of downwardly projecting stiff ening ribs 35, one rib being aligned with each of the respective bosses 23 through 28. Each of these ribs is provided with a suitable bore 36 through which extends a suitable fastener such as bolt 37 for securing the apparatus 13 to a plurality of fin structures 38 for providing thermal transfer to the ambient atmosphere at the rear of the cabinet 11. As best seen in FIGURE 1, one fin structure 38 is associated with each of the respective bosses and thermoelectric element combinations. Thermal transfer between the thermoelectric elements and the bosses and root portion 39 of the fin devices may be improved by applying a suitable heat transfer compound as at 40 and 41, one example of such a compound being Dow Corning No. 340 heat sink compound. As shown in FIGURE 4, the upper portion of the panel 20 is secured to the root portion 39 of the fin devices 38 by suitable fastening devices, e.g. bolts, 42 passed through an upper stiffening rib 43 associated with each of the bosses 26, 27 and 28, and an elongated upper stiffening rib 44 (FIGURE 3) associated with each of bosses 23, 24 and 25.

Integrally with the panel 26 is a block of insulation 45 which, as shown in FIGURES l, 3 and 4, effectively surrounds the bosses 23 through 28. The insulating material may be foamed in place to adhere to the panel and bosses. Suit-able recesses 46 may be provided in the rear of the block to receive the thermoelectric devices 29 through 34. Thus, the thermoelectric devices 29 through 34 are readily installed in the insulation block and may be readily removed such as for servicing, thereby providing a substantial advantage over the known structures wherein the thermoelectric modules are substantially permanently associated with the insulating block by virtue of the block being soldered in place about the modules. Such a soldered in place construction makes it very difficult to service the thermoelectric modules without damaging the modules, the associated wiring, or the insulation surrounding the modules.

In the instant structure, additional recesses may be provided in the rear of the block for receiving wiring 47. Thus, here again, facilitated servicing of the wiring to the thermoelectric devices is provided permitting the wiring to be displaced rearwardly from the insulating block when desired, as during servicing of the thermoelectric elements.

To seal the chamber 1%, suitable sealing compound 48 may be applied between the block 45, the fin root 39, and the insulation 49 in the cabinet wall 14, and suitable sealing compound 59 may be applied between the block 45, insulation '49, and inner liner 51 of the cabinet. Additionally, sealing compound 52 may be placed between the respective fin assemblies. The roots 39 of the respective fins may be secured to the outer panel 53 of the cabinet 11 by suitable screws 54.

Thus, the apparatus 1% may be readily installed in a suitable opening 55 in the rear wall 14 of the cabinet 11. The assembled arrangement of the panel 2%} and shelves 21 and 22 with the insulating block 45 adhered thereto and fins 38 secured thereto with the thermoelectric elements 29 through 34 installed in the recesses 46 may be simply moved forwardly through the opening 55 to the position shown in FTGURE 4 and retained in this position by the screws 54. If at any time servicing of the thermoelectric elements is desired, the fins may be removed from the assembly by suitable manipulation of bolts 37 and 52 and screws 54 providing rear access to the thermoelectric elements and wiring 47.

The thermoelectric elements are arranged in a novel manner to provide an improved shelf cooling and chamber coooling functioning. More specifically, the thermoelectric elements 32, 33 and 34 are cascaded in the well known manner to provide a greater temperature differential at the portion of panel 20 to which the shelves 21 and 22 are connected. The thermoelectric elements 29, 34? and 31 are single stage elements whereby the panel portion adjacent bosses 23, 24 and 25 is refrigerated to a lesser extent as compared to the portion adjacent the shelves 2]. and 22. Thus, the chamber 18 is refrigerated primarily by the lesser cooling structure defined by the panel portion refrigerated by the single stage thermoelectric elements, whereas the shelves 2i and 22 are maintained at a lower temperature by the cascaded thermoelectric elements. As the panel area is substantially greater than the shelf area, the panel structure provides the primary heat transfer surface for cooling of the chamber 18 with a preselected additional heat transfer surface being effected by the shelves.

Referring now to the wiring diagram shown in FIG- URE 5, the operation of the apparatus 19 in causing the apparatus It to operate as a refrigerator is as follows. The thermoelectric elements 29 through 34 are connected in series between a first end conductor 56 and a second end conductor 57 which are connected through a conventional quick disconnect terminal block 58 to a conventional pushbutton switch 59. More specifically, conductor 56 is connected through the block 58 to a conductor 60 connected to a first fixed contact 61a of a first single pole, double throw switch 61 and a first fired contact 62a of a second single pole, double throw switch 62. Conductor 57 is connected through the block 53 to a conductor 63 connected to. a second fixed contact 61b of switch 61 and a second fixed contact 62b of switch 62. The moving contact 61c of switch :61 is connected through a choke st to a pair of diodes es connected to the opposite ends of the secondary winding 66a of a transformer 66. A capacitor 67 is connected across the ends of the secondary winding. The moving contact 62c of switch 62 is connected to a center tap es of transformer secondary 65a. The primary 66b of the transformer 66 has one end connected to a power supply lead L and the other end connected through a heating thermostat 69 of conventional construction to a first fixed contact 76a of a single pole, double throw switch "iii, also part of pushbutton switch 59. A tap 71 on transformer primary 55b is connected through a cooling thermostat 72 to a second fixed contact 7G1) of switch 7h. The moving contact 76c of switch 76 is connected in series with a single pole, normally open off-on switch 73 to a safety thermostat 74 which is juxtaposed to boss 28 to sense the specific temperature of that position. The other side of the safety thermostat 7 2 is connected to a conductor 75 which in turn is connected to the other power supply lead L through a fuse 76. The pushbu'tton switch 59 includes a manual operator 59a for selectively operating the moving contacts 61c, 62c and 74% of the switches 61, 62 and 70', respectively. In the illustrated arrangement, the switches are shown in the heating position in full lines and in the cooling position in dotted lines.

Thus, assuming that the temperature in chamber 18 is somewhat higher than desired and the apparatus is connected by power supply lead L and L to a suitable power source, current will flow through the primary 4%]? of the transformer 65 and thermostat 72, which is now closed, through the contacts 701; and 70c of the switch 76, through on-ofi switch 73 and safety thermostat 74 to the other side of the power supply thereby energizing the secondary Winding 66a of the transformer. The diodes 65 provide a rectified or direct current conducted through the switches 61 and 62- in suitable direction as indicated by the arrows to cause the thermoelectric elements 29 through 34 to transfer heat from the bosses 23 through 28 to the fins 38 for cooling the panel 20 and shelves 2i and 22.

When the temperature within chamber 18 is lowered sufficiently to cause thermostat 72 to open, the circuit to the thermoelectric elements is broken, thereby discontinuing the energization thereof. At such time as the temperature sensed by the thermostat 74 rises above the preselected level, the thermostat 74 closes and the above described circuit is again established.

When it is desired to utilize the apparatus 10 as an oven, the operator merely operates pushbutton operator 59a to throw the switches 61, 62 and 70 to the full line position of FIGURE 5, whereupon the current is directed through the thermoelectric devices 29 through 34 in an opposite direction causing them to heat the bosses 23 through 28 and thereby, in turn, heat the panel 20 and shelves 21 and 22. The heating operation is under the control of the heating thermostat 69 which regulates the temperature within the apparatus. If desired, the pushbutton switch 59 may be operated to the heating position for a predetermined time period to effect a defrosting of the apparatus when used as a refrigerator.

Thus, the apparatus 10 provides a simple and economical heat transfer structure which is readily installable and removable relative to cabinet 11. The panel and shelf arrangement provides an improved heat transfer between the chamber defined by the cabinet and objects placed on the shelves. As the thermoelectric elements are connected in series, a preselected relationship between the shelf temperature and the temperature of the chamber is automatically obtained. The apparatus is readily selectively operable to provide a heating function as well as a refrigeration function at the choice of the user.

While we have shown and described one embodiment of our invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as defined in the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Heat transfer appartaus comprising: means defining a chamber; means defining a heat transfer body having an integral heat transfer panel and shelf in heat transfer association with each other and with said chamber;

means for causing a first temperature difference between a first portion of said panel and said chamher to cause a heat transfer therebetween; and

means for causing a second temperature difference between a second portion of said panel and said shelf for causing a temperature difference, greater than said first temperature difference, between said shelf and said chamber to cause a heat transfer therebetween.

2. The heat transfer apparatus of claim 1 wherein said panel has an area exposed to said chamber greater than the area of said shelf exposed to said chamber.

3. The heat transfer apparatus of claim 1 wherein said panel and shelf comprise a monolithic structure.

4. Heat transfer apparatus comprising:

means defining a chamber;

means defining a heat transfer body having juxtaposed first and second portions in heat transfer association with each other and with said chamber;

means for causing a first temperature difference between said first portion of the body and said chamber to cause a heat transfer therebetween; and

means for causing a second temperature difference,

greater than said first temperature difference, between said second portion of the body and said chamber to cause a heat transfer therebetween.

5. Heat transfer apparatus comprising:

means defining a chamber;

means defining a heat transfer body having juxtaposed first and second portions in heat transfer association with each other and with said chamber;

means for causing a first temperature difference between said first portion of the body and said chamber to cause a heat transfer therebetween;

means for causing a second temperature difference,

greater than said first temperature difference, between said second portion of the body and said chamber to cause a heat transfer therebetween; and means for selectively alternatively causing said temperature differences to be positive and negative.

6. The heat transfer apparatus of claim 5 wherein said means for causing temperature differences comprise thermoelectric means.

7. The heat transfer apparatus of claim 5 wherein said means for causing a first temperature difference comprise single stage thermoelectric means and said means for causing a second temperature difference comprises cascaded multistage thermoelectric means.

8. Heat transfer apparatus comprising:

means defining a chamber;

means defining a heat transfer body having juxtaposed first and second portions in heat transfer association with each other and with said chamber;

means for causing a first temperature difference between said first portion of the body and said chamber to cause a heat transfer therebetween; means for causing a second temperature difference,

greater than said first temperature difference, between said second portion of the body and said chamber to cause a heat transfer therebetween; and

means removably carrying said heat transfer body and each of said temperature difference causing means as a unitary assembly on said chamber means.

9. Heat transfer apparatus comprising:

means defining a chamber including a wall formed of insulating material and having an outwardly opening recess;

means carried on the inner surface of said wall and defining a heat transfer body in heat transfer association with said chamber; and

a plurality of thermoelectric elements severally sepa rably received in said recess for causing a temperature difference between said heat transfer body and said chamber to cause a heat transfer therebetween.

10. Heat transfer apparatus comprising:

means defining a chamber including a wall formed of insulating material and having an outwardly opening recess and an outwardly opening groove extending away from said recess;

means carried on the inner surface of said wall and defining a heat transfer body in heat transfer association with said chamber;

thermoelectric means severally separably received in said recess for causing a temperature difference between said heat transfer body and said chamber to cause a heat transfer therebetween;

wiring means separably received in said groove and electrically connected to said thermoelectric elements for selectively conducting electrical energy thereto; and a thermally conductive member closing said recess and said groove.

11. Heat transfer apparatus comprising:

means defining a chamber;

means defining a heat transfer panel having an integral shelf in heat transfer association with said chamber;

insulation means disposed adjacent said panel and having a plurality of preformed recesses therein;

means defining a finned heat transfer assembly in heat transfer association with the ambient atmosphere and having a root portion closing said recesses;

first thermoelectric module means located between said heat transfer panel and said root portion of the finned heat transfer assembly and in a portion of said plurality of recesses for causing a predetermined temperature difference between said chamber and said heat transfer panel; and

second thermoelectric module means located between said heat transfer panel and said root portion of the heat transfer assembly and in a portion of said plurality of recesses adjacent said shelf for causing the temperature of said shelf to be substantially less than the temperature of said heat transfer panel.

References Cited by the Examiner UNITED STATES PATENTS 2,970,450 2/1961 Roeder 623 2,978,875 4/1961 Lackey 62-3 3,040,539 6/1962 Gaugler 62-3 3,077,079 2/ 1963 Pietsch 623 3,136,577 6/1964 Richard 623 WILLIAM J. WYE, Primary Examiner. 

1. HEAT TRANSFER APPARATUS COMPRISING: MEANS DEFINING A CHAMBER; MEANS DEFINING A HEAT TRANSFER BODY HAVING AN INTEGRAL HEAT TRANSFER PANEL AND SHELF IN HEAT TRANSFER ASSOCIATION WITH EACH OTHER AND WITH SAID CHAMBER; MEANS FOR CAUSING A FIRST TEMPERATURE DIFFERENCE BETWEEN A FIRST PORTION OF SAID PANEL AND SAID CHAMBER TO CAUSE A HEAT TRANSFER THEREBETWEEN; AND MEANS FOR CAUSING A SECOND TEMPERATURE DIFFERENCE BETWEEN A SECOND PORTION OF SAID PANEL AND SAID SHELF FOR CAUSING A TEMPERATURE DIFFERENCE, GREATER THAN SAID FIRST TEMPERATURE DIFFERENCE, BETWEEN SAID SHELF AND SAID CHAMBER TO CAUSE A HEAT TRANSFER THEREBETWEEN. 